DESCRIPTION

Technical field

The present invention relates to a vibration pump for pumping a fluid, which can be used, for example, in machines for making coffee, tea or other beverages. Besides, the pump can also be used in other apparatus, such as household appliances .

Background art

It is known in the art that in some situations it is necessary to measure the flow rate of the fluid being delivered by the vibration pump, e.g. when the pump is delivering water for preparing a cup of coffee. Determining the flow rate is useful for dosing a predetermined quantity of beverage into a vessel. In some beverage-dosing devices, a flowmeter, e.g. comprising an impeller, is connected upstream of the pump by means of a tube.

However, systems of this type suffer from a few drawbacks .

One drawback lies in the fact that the assembly consisting of the pump and the flowmeter is bulky.

Another drawback lies in the fact that, when the pump is not in use, a large quantity of liquid remains for a long time in the tube that connects the pump to the flowmeter, resulting in such liquid remaining exposed to the outside environment (which contains bacteria, dust, etc.), which leads to hygiene problems, especially when the pump is used in a beverage-dispensing machine, such as a coffee-making machine .

Summary of the invention

It is one object of the present invention to provide a vibration pump which can overcome this and other drawbacks of the prior art, while at the same time being simple and economical to manufacture.

According to the present invention, this and other objects are achieved through a vibration pump made in accordance with the appended independent claim.

It is to be understood that the appended claims are an integral part of the technical teachings provided in the following detailed description of the present invention. In particular, the appended dependent claims define some preferred embodiments of the present invention, which include some optional technical features.

Brief description of the drawings

Further features and advantages of the present invention will become apparent from the following detailed description, which is supplied merely by way of non-limiting example with reference to the annexed drawings, wherein:

- Figure 1 is a longitudinal sectional view of a pump in accordance with an exemplary embodiment of the present invention;

- Figure 2 is a perspective view of a pump according to an exemplary embodiment of the present invention;

- Figure 3 is a perspective view of the pump of Figure 2, with the cover removed;

- Figure 4 is a perspective view of the cover with the impeller of a pump according to an exemplary embodiment of the present invention;

- Figure 5 is another longitudinal sectional view of a pump in accordance with an exemplary embodiment of the present invention;

- Figure 6 is a perspective view of a pump according to an embodiment of the invention, showing the inside of the cylinder ;

- Figure 7 is a perspective view of a pump made in accordance with another embodiment of the present invention;

- Figure 8 is a side view of the pump of Figure 7;

- Figure 9 is a longitudinal sectional view of the pump shown in Figures 7 and 8 along line IX-IX of Figure 8;

- Figure 10 is another longitudinal sectional view of the pump shown in Figures 7 to 9 along line X-X of Figure 7; and

- Figure 11 is an exemplary block diagram of electronic control means of the pump shown in Figures 7 to 10.

Detailed description of the invention

The invention concerns a vibration pump (hereafter also referred to simply as "pump") . In particular, said pump substantially extends along a longitudinal axis x-x. Therefore, the terms "axial", "longitudinal", "transversal" and "radial" as used in the following description should be considered to refer to said longitudinal axis x-x.

The pump comprises:

- a core 2 at least partially made of ferromagnetic material ,

- a solenoid 4 for actuating core 2,

- a cylinder 6 comprising a work chamber 7 in which core

2 can slide,

- an inlet duct 8 and an outlet duct 10, allowing a fluid to flow in cylinder 6,

- valve means for generating the flow of fluid from inlet duct 8 to outlet duct 10 when core 2 reciprocates in cylinder

6 ;

- flow-rate measuring means integrated into said pump for measuring the flow rate of the fluid being delivered by the pump .

In particular, the pump has elastic means, such as a spring 11, for bringing core 2 into an idle position when said core 2 is not subject to the magnetic action of solenoid

4. As is known, solenoid 4 is adapted to generate a time- variable magnetic field in order to move core 2, which, by co-operating with the elastic means, will move in a reciprocating manner, covering a stroke within cylinder 6. Preferably, one end of spring 11 is constrained to core 2 (e.g. by welding or other mechanical constraints) in both directions of sliding of said core 2, and therefore it 11 can work both under traction and under compression. Hence, in the illustrated example spring 11 is compressed when core 2 is subject to the magnetic field generated by solenoid 4, and, when the magnetic field stops, spring 11 releases the previously accumulated energy and holds core 2 by means of a tensile force. Optionally, a second spring may be employed, operating on the other side of core 2. In such a case, the two springs 11 may simply rest on the bases of core 2, in accordance with the prior art.

Solenoid 4 is in a radially external position relative to core 2. Advantageously, at least one ferromagnetic element

5, conveniently made of metal, is interposed between solenoid 4 and core 2. In the example there are two ferromagnetic elements 5, which preferably have the shape of an arc of circumference, or a "C" shape. The at least one ferromagnetic element 5 is arranged circumferentially around core 2. Ferromagnetic element 5 may be a permanent magnet. Core 2 is conveniently made of metallic material. Solenoid 4 is conveniently housed in a respective housing or casing 40 mounted to cylinder 6.

The valve means are configured in a manner such as to generate a flow of fluid exiting outlet duct 10 as core 2 moves in cylinder 6. In particular, there are a first valve 12 and a second valve 14, the latter being positioned near outlet duct 10. The second valve 14 is actuated by a respective spring 15. The illustrated valves 12, 14 are non return valves. In particular, the first valve 12 is adapted to co-operate with core 2.

In particular, cylinder 6 comprises a second chamber 9, in which the fluid is intended to flow, and which is fluidically connected to work chamber 7 and to outlet duct 10. The second chamber 9 and outlet duct 10 communicate through an aperture intended to be occluded by the second valve 14. The second chamber 9 is located downstream of work chamber 7, with reference to the fluid flow. In particular, core 2 has a cavity and is associated with a tube 16 that puts work chamber 7 in fluidic communication with the second chamber 9 as the fluid flows through said cavity of core 2. Tube 16 (or at least a part thereof) is slidably and sealingly housed in the second chamber 9. In the example a gasket 19 is shown. Conveniently, the cross-section of work chamber 7 is bigger than that of the second chamber 9. In particular, said chambers 7, 9 are substantially cylindrical in shape .

As is known, core 2 defines, in work chamber 7 of cylinder 6, an inlet chamber 36 and a compensation chamber 38, which are intended to be filled with fluid. When the pump is in operation, the fluid enters work chamber 7 through inlet duct 8, then flows along tube 16 and into the second chamber 9 through the first valve 12, and finally exits through the second valve 14 and outlet duct 10. Chambers 36, 38 are generally in fluidic communication with each other, so that, during the reciprocating motion of core 2, the fluid or liquid will flow between said chambers 36, 38, thus reducing the resistance to motion of core 2. During the reciprocating motion of core 2, the volume of chambers 36, 38 varies .

By way of example, and with reference to Figure 1, the following will briefly describe the operation of the illustrated pump. When spring 11 is compressed through the effect of the magnetic field generated on core 2 by solenoid 4, the volume of inlet chamber 36 is reduced (in Fig. 1, core 2 is moving to the left), and the pressure drop generated by the expansion of the second chamber 9 opens the first valve 12, thereby causing the liquid to flow into the second chamber 9. At this stage, compensation chamber 38 has a greater volume. When the action of solenoid 4 ends, spring 11 releases the accumulated elastic energy and pushes core 2 towards the idle position (in Fig. 1, core 2 is moving to the right), thereby increasing the volume of the inlet chamber 36. At this stage, the first valve 12 is closed, and the displacement of core 2 towards the idle position increases the pressure in the second chamber 9, which causes the second valve 14 to open, thus allowing the liquid to flow out through outlet duct 10. At this stage, compensation chamber 38 has a smaller volume.

In the example there is a tube 16 housed in an internal cavity of core 2 and rigidly constrained to said core 2. The first valve 12 is arranged inside tube 16, and includes, in particular, a shutter, in particular a ball, intended to abut on a narrower section, in particular under the action of a spring 18 constrained to one end of tube 16. As an alternative, the ball is pushed towards the narrower section under its own weight force, e.g. when the pump is tilted, in particular when said pump is arranged vertically. In particular, the narrower section is formed integrally with tube 16. In tube 16 a fluid is intended to flow. The narrower section is adapted to be occluded by the shutter, e.g. under the action of spring 18. In the particular example shown, tube 16 and core 2 are two distinct elements mechanically constrained to each other; such a solution is simple and economical to produce. In particular, tube 16 is configured in a manner such that the fluid, as it flows in said tube 16, passes from inlet chamber 36 to the second chamber 9. Thus, the fluid cannot flow from compensation chamber 38 to the second chamber 9 through the side walls of tube 16. In fact, the side walls of tube 16 have no apertures allowing the fluid to pass directly from compensation chamber 38 to the inside of tube 16. In this case, according to one possible embodiment, chambers 36, 38 may be in fluidic communication through a channel, or duct, running through core 2. Said through channel is distinct from the cavity that houses tube 16.

In accordance with further variants, core 2 and tube 16 may be made as one piece. In addition or as an alternative, according to one variant tube 16 has at least one aperture for putting the inside of tube 16 in fluidic communication with compensation chamber 38. In this case, the fluid entering tube 16 will flow partly into compensation chamber 38 and partly into the second chamber 9. According to such a variant, it is no longer necessary, although still possible, to create an additional communication passage or duct between chambers 36, 38.

In a first embodiment, the flow-rate measuring means are arranged upstream of core 2, in particular upstream of work chamber 7, with reference to the fluid flow. The fluid is generally a liquid, e.g. water. In particular, the flow- rate measuring means comprise:

- an impeller 20 located between core 2 and inlet duct 8, and intended for being turned by a flow of fluid entering through inlet duct 8 and directed towards work chamber 7,

- sensing means 24 for sensing the rotation of impeller 20, for the purpose of measuring the fluid flow rate.

Preferably, impeller 2 comprises at least one magnet 22, and sensing means 24 are adapted to sense the rotation of magnet 22 in order to measure the fluid flow rate.

Sensing means 24, which may be per se known, are adapted to sense magnetic field variations caused by the rotation of impeller 20 and of magnet 22 integral therewith.

For example, the sensing means may be of the electric, electronic or magnetic type, such as, for example, a magnetic sensor. Impeller 20 is adapted to rotate about an axis of rotation x-x, which is, in particular, coaxial to the axis of core 2 (which in the illustrated example is the sliding axis of core 2) . Impeller 20 is conveniently supported in rotation by a support 26. Support 26 may be, for example, made of ferromagnetic, in particular metallic, material (preferably magnetic steel); as an alternative, support 26 may be made of plastic material. Said support 26 has a pin 28 inserted in a matching recess in impeller 20 to allow rotation thereof. As can be noticed, the pump is very compact, and there is no need for a long tube connecting outlet duct 10 or inlet duct 8 to an external flowmeter, in which the fluid, e.g. water, may stagnate. This aspect is particularly advantageous in beverage dispensers, wherein it is advantageous to prevent the liquid from remaining in contact with the outside environment for long periods of time; also, this prevents undesired dripping. According to possible variants, sensing means 24 are optical ones, e.g. for reading reading portions (e.g. differently coloured stripes or other distinctive marks) on impeller 20. Preferably, impeller 20 has only one magnet 22, the two magnetic poles of which lie in a plane transversal to axis x-x of rotation of impeller 20. This variant offers the advantage that it is both compact and inexpensive, since there is only one magnet 22. Besides, the transversal orientation of magnet 22 allows reducing the height of the impeller. Furthermore, the presence of just one magnet 22 allows reducing the revolving masses, and hence any possible vibrations .

In accordance with one possible variant, the diameter of impeller 20 is shorter than the width of work chamber 7, with reference to a plane transversal to the axis of rotation x-x of impeller 20 (which, in the illustrated embodiment, coincides with the axis of core 2) . As aforementioned, in the illustrated example the (sliding) axis of core 2 coincides with axis x-x. In particular, the diameter of impeller 20 is smaller than the inside diameter of work chamber 7. In the particular embodiment shown herein, the cross-section of work chamber 7 is circular in shape. In this manner, when the pump is arranged substantially horizontally (as in Fig. 1), any air bubbles or pockets within it will not come in contact, or will only make little contact, with impeller 20, thus ensuring a more accurate measurement. In fact, air will tend to stay above the liquid (e.g. water), and when air is formed in the pump, e.g. during the initial phases of operation, the air will tend to go into cylinder 6, or will tend to remain in a region of an impeller housing chamber 30 where said impeller 20 will not touch the air or where any contact between impeller 20 and the air will be limited. Impeller 20 can thus rotate while staying immersed in the liquid.

Preferably, impeller 20 is housed in a housing chamber 30 that is fluidically connected to inlet duct 8 and to work chamber 7. The width of housing chamber 30, measured in a plane transversal to axis x-x of rotation of impeller 20 (which, in the illustrated embodiment, coincides with the axis of core 2) is shorter than the inside diameter of work chamber 7. In this manner, when the pump is arranged substantially horizontally (as in Fig. 1), any air bubbles or pockets within it will tend to go into cylinder 6 where core 2 slides, and therefore housing chamber 30 will remain free of air bubbles or with only a minimal quantity of air. In particular, the pump includes a cover 32 removably mounted (e.g. by means of screws 33) to cylinder 6, between which a gasket 34 is conveniently interposed. In cover 32 housing chamber 30 is formed. Housing chamber 30 is defined by cover 32 and by cylinder 6. Moreover, the illustrated cover 32 comprises inlet duct 8. Conveniently, sensing means 24 are associated with cover 32. Conveniently, inlet duct 8 is configured to direct a flow of fluid tangentially onto impeller 20, particularly onto blades of impeller 20.

In the example, housing chamber 30 fluidically communicates with the inside of cylinder 6 through at least one passage 41. In particular, said passages 41 are formed on support 26. In particular, support 26 has a substantially flat circular base, whereon passages 41 are evenly distributed .

In accordance with one possible variant, the pump is comprised in an apparatus, such as a beverage-dispensing machine or a coffee-making machine, and, when said apparatus is resting on a horizontal surface, cylinder 6, and in particular work chamber 7, is tilted relative to a horizontal plane, e.g. by an angle of 10° to 80°, preferably 10° to 60°, more preferably 10° to 30°. In this way, it is advantageously possible to facilitate the elimination of the air from housing chamber 30 that houses impeller 20, thus making the measurement more accurate. In particular, work chamber 7 as a whole is situated in a higher position than impeller 20 or housing chamber 30. For example, the tilted position corresponds to the position taken by the pump of Figure 1 when it is turned counterclockwise by a few degrees. Thus, impeller 20 can rotate while staying immersed in the liquid. Cylinder 6, and in particular work chamber 7, is arranged on a longitudinal axis, which in particular coincides with axis x-x. Therefore, axis x-x can be tilted relative to the horizontal.

With reference to Figures 5 and 6, there is shown a particular communication duct 42 between chambers 36, 38. An inner surface of cylinder 6, which defines work chamber 7, comprises at least one recess defining communication duct 42. Preferably, the recess is substantially parallel to a longitudinal axis of the work chamber, which in particular coincides with axis x-x. Therefore, communication duct 42 is substantially parallel to axis x-x. In particular, the pump includes a plurality of (in the example, two) communication channels 42, which are preferably distributed evenly on the inner surface of work chamber 7. In the example, the two communication channels 42 are located in diametrically opposite positions. In a cross-section, the recess on the inner surface of cylinder 6 is an open channel. Core 2 and the recess on the inner surface of cylinder 6 create communication duct 42, which is therefore a closed channel. In the particular variant shown herein, the at least one communication duct 42 is present along substantially the entire length of work chamber 7. In such embodiment, the diameter of impeller 20, and preferably also the width of housing chamber 30, are smaller than the width of work chamber 7, which 7 comprises also communication duct 42.

In accordance with one variant of the invention, the pump comprises a communication duct that fluidically connects inlet chamber 36 and compensation chamber 38 in a manner such that, when the pump is in operation, the fluid will flow into said communication duct. The flow-rate measuring means are adapted to sense the motion of the fluid in the communication duct, in order to measure the flow rate of the fluid being delivered by the pump. When core 2 is reciprocating in cylinder 6, an alternate to-and-fro motion of the fluid is generated in the communication duct because of the pressures generated in inlet chamber 36 and in compensation chamber 38 due to the reciprocating motion of core 2 along its stroke. Therefore, the flow-rate measuring means are adapted to sense such motion of the fluid in the communication duct, for the purpose of calculating the flow- rate of the fluid being delivered by the pump. The pump is thus quite compact, since it is no longer necessary to mount a flowmeter downstream or upstream of the pump, and fluid compensation between chambers 36, 38 can be exploited for calculating the flow rate of the pump.

Preferably, the flow-rate measuring means comprise: a mobile body located in the communication duct and configured for being moved by the fluid in motion in said communication duct, and a sensor for sensing the motion of said mobile body. In particular, the mobile body is at least partially magnetic, and the sensor is a magnetic sensor. For example, the mobile body is, or comprises, a magnet, or is at least partially metallic. Therefore, the magnetic sensor is adapted to count the strokes of the mobile body, in particular by sensing the magnetic field variations, in order to calculate the flow rate of the fluid being delivered by the pump. In accordance with one embodiment, the fluid is allowed to pass between the mobile body and the communication duct. In particular, in a cross-sectional view, the mobile body is smaller than the inner surface of the communication duct. In any case, the mobile body and the communication duct are shaped in such a way that the mobile body is moved by the fluid in motion in the communication duct. According to one possible variant, the mobile body is slidably and sealingly housed in the communication duct.

Preferably, the mobile body and the communication duct are so configured as to limit the travel of the mobile body in the communication duct. For example, the communication duct has internal travel-limiting portions (such as, for example, a protrusion, a pin or a cross-shaped element) capable of limiting the travel of the mobile body while still allowing the fluid to flow.

In particular, the communication duct communicates with inlet chamber 36 and compensation chamber 38 through a first aperture and, respectively, a second aperture. The communication duct is a duct running through the body of cylinder 6. Therefore, the communication duct is essentially a tube, the ends of which face (thanks to said apertures) into the internal part of cylinder 6 in which core 2 slides.

Preferably, cylinder 6 comprises, on its outer surface, a protrusion 46, in particular annular in shape, for keeping the two ferromagnetic elements 5 spaced apart. Such protrusion 46 is formed integrally with cylinder 6. Protrusion 46 is arranged transversally to axis x-x .

Preferably, core 2 has a substantially circular cross- section. More preferably, the inner cavity of core 2 also has a substantially circular cross-section. In the illustrated embodiment, the pump comprises control means configured for receiving signals from the sensing means, and for controlling solenoid 4, in particular as a function of such signals.

By way of example, the apparatus in which the pump according to the present invention can be installed may comprise electronic control means, in particular a control circuit, preferably mounted on the pump itself. The pump of the present invention can be employed, for example, in coffee-making machines, tea-making machines or, in general, in a machine for dispensing liquids or beverages. Besides, the pump can also be used in other apparatus, such as household appliances.

With reference to Figures 7 to 11, there is shown a further exemplary embodiment of the present invention.

As far as core 2, cylinder 6 in which core 2 slides, inlet duct 8 and outlet duct 9, the valve means (comprising, for example, the first valve 12 and the second valve 14) and the flow-rate measuring means (comprising, for example, impeller 20 and sensing means 24) are concerned, they can be made in any one of the above-described ways. Therefore, for brevity's sake they will not be described any further below, and reference should be made to the previous explanations contained in this description.

Figures 7 and 8 are views of the pump made in accordance with said further embodiment, wherein said pump comprises electronic control means 50 integrated into it.

As will be further explained hereinafter, electronic control means 50 are solidly mounted to cylinder 6. In particular, electronic control means 50 are rigidly constrained to said cylinder 6. More in particular, electronic control means 50 are mounted in a manner such as to vibrate at substantially the same frequency as cylinder

6.

In the illustrated embodiment, electronic control means 50 are positioned laterally relative to cylinder 6.

Preferably, also with reference to, for example, Figures 9 and 10, electronic control means 50 are supported by a casing 40 mounted on cylinder 6, in which also solenoid 4 is housed; in particular, casing 40 that contains solenoid 4 surrounds cylinder 6. More preferably, casing 40 defines a cavity 52 (e.g. situated laterally relative to cylinder 6), in which electronic control means 50 are housed. Even more preferably, electronic control means 50 are buried into a resin (not shown) injected in cavity 52.

The presence of the resin in cavity 52 containing electronic control means 50 offers the advantage of further improving the tightness of the union between electronic control means 50 and casing 40.

Furthermore, such resin reduces the frequency and amplitude of the vibrations that can be transmitted to the system, thereby also reducing noise in general.

Moreover, advantageously but not necessarily, such resin may be made of a thermally conductive material or type, so as to promote heat dissipation due to the Joule effect in electronic control means 50.

In the illustrated embodiment, casing 40 may be made as one piece by moulding a plastic material, or may consist or a plurality of pieces of plastic material, distinct from one another and connected together in a way per se known, e.g. by mechanical interference (in particular, by press-fitting) or the like.

In the illustrated embodiment, electronic control means

50 are configured for: - receiving signals indicative of the flow rate of the fluid being delivered by the pump, generated by the flow- rate measuring means (e.g. impeller 20 and sensing means 24) , and

- controlling solenoid 4 as a function of said signals.

Such electronic control means 50 are also configured for receiving a control signal coming, for example, from a user interface, as a function of which (and also of the signals indicative of the fluid flow rate) solenoid 4 is controlled .

In the illustrated embodiment, electronic control means 50 comprise a printed circuit board 54.

Preferably, with particular reference to Figure 11, printed circuit board 54 comprises a power supply module 56 configured for supplying electric energy, in particular to solenoid 4. In particular, the connectors of solenoid 4 are directly plugged into printed circuit board 54 and electrically connected to power supply module 56.

Particularly, printed circuit board 54 comprises also a controller module 58 connected to power supply module 56, to the flow-rate measuring means (in particular, to sensing means 24), and to solenoid 4. Controller module 58 is configured for receiving signals from the flow-rate measuring means, and for causing power supply module 56 to supply, in a controlled manner, the electric energy to solenoid 4 as a function of said signals.

In the illustrated embodiment, printed circuit board 54 comprises a thermal protection module 60 electrically connected in series between power supply module 56 and solenoid 4. Thermal protection module 60 interrupts the electric connection between solenoid 4 and power supply module 56 when the temperature of thermal protection module 60 exceeds a predetermined safety threshold value.

Preferably, printed circuit board 54 has at least one component, e.g. a triac 62, abutting on skirt 64 of solenoid 4, in particular on a side 65 thereof that faces into cavity 52. Advantageously but not necessarily, side 65 of skirt 64 may be the bottom of cavity 52 formed in casing 40.

Triac 62 can thus dissipate the accumulated heat through skirt 64.

In particular, triac 62 electrically co-operates with solenoid 4 and/or with other electric devices external to printed circuit board 54, e.g. an external boiler of a household appliance. In the illustrated embodiment, a portion of skirt 64 is buried into casing 40, and said component, e.g. triac 62, is housed in a seat 66 formed in cavity 52 of said casing 40. In particular, seat 66 is defined by walls 67 protruding from the bottom of cavity 52 and acting as spacer elements whereon printed circuit board 54 rests.

In the illustrated embodiment, printed circuit board 54 is connected to another secondary printed circuit board 69 that comprises the flow-rate measuring means, e.g. sensing means 24. Preferably, the secondary printed circuit board 69 is positioned transversally, in particular substantially perpendicularly, to printed circuit board 54. For example, the secondary printed circuit board 69 is connected by means of electric connectors 71 plugged into printed circuit board 54.

In further variant embodiments, as described above with reference to additional printed circuit board 69, a person skilled in the art may conceive electronic control means 50 comprising a plurality of secondary printed circuit boards connected to printed circuit board 54. The electric connection between said secondary printed circuit boards and printed circuit board 54 may be achieved through numerous per se known methods; for example, by welding electrically conductive terminals, by plugging electric connectors, or through connections obtained by means of electric wires.

In the illustrated embodiment, the components of printed circuit board 54 advantageously face towards the inside of cavity 52 (in other words, towards cylinder 6) . This arrangement protects such components against the environment outside the pump.

Preferably, electronic control means 50 are configured for being connected to external devices of a household appliance, e.g. through a plurality of external cables, contacts or connectors 68. In the illustrated embodiment, the external contacts or connectors 68 protrude past casing 40.

In particular, the external devices may be of different types and perform any function. Merely by way of example, such external devices may comprise at least one element selected from the list including a user interface 70, a temperature sensor 72 and a level sensor 74 associated with the fluid to be dispensed (e.g. contained in a tank), a data connection module 76 (e.g. a Wi-Fi module), a valve for the fluid to be dispensed 78 (e.g. associated with a tank containing the fluid to be dispensed) , an anti-dripping device 80 (e.g. associated with the fluid outlet of the household appliance), an automatic device for expelling capsules 82, a boiler or heater 84, a valve for steam 86 generated by the boiler or heater.

Advantageously, controller module 58 may be connected to respective controllers of the external devices, so as to control the operation of such controllers, e.g. in accordance with a master/slave hardware architecture.

Of course, without prejudice to the principle of the invention, the forms of embodiment and the implementation details may be extensively varied from those described and illustrated herein by way of non-limiting example, without however departing from the scope of the invention as set out in the appended claims.

The technical features that differentiate the different variants and embodiments described and illustrated herein can, when compatible, be freely interchanged. In particular, as will be apparent to a person skilled in the art, the structure and configuration of electronic control means 50 described for the embodiment illustrated in Figures 7 to 11 are applicable to the embodiment ( s ) of the pump illustrated in Figures 1-6.